125. CoMPOsiTAE 247 



l.Lea\es not decunent : achenes 1.5-2 mm long'; phyllaries linrar- 

 subulate. 



2. Leaves lanceolate to oblanceolate, 0.5-2 cm broad, the upper 

 smaller; disk 5-8 mm broad; alluvial soil, river banks, or wet 

 ground in woods, locally throughout 111. Aug-Oct. [B. aste- 



roides sensu auth., non (L.) L'Her.] 



B. recognita (Fern. & Grisc.) G. N. Jones 



2. Leaves linear, 1-5 mm wide, those of the branchlets subulate; 

 disk 3-5 mm broad ; dry soil in the southern part of the state, 

 extending northward to St. Glair, Fayette, and Crawford 



counties. Aug. -Sept. [B. diffusa sensu auth., non Ell.] 



B. interior (Fern. & Grisc.) G. N. Jones 



19. Aster L. — Aster 



1. Heads radiate; plants perennial. 



2. Lower leaves cordate or subcordate, long-petioled. 

 3. Leaves nearly all sharply serrate. 



4. Heads corymbose; involucral bracts obtuse, the outer 1-2 



mm wide, ciliolate and more or less puberulent; achenes 



linear. 



5. Peduncles (and involucres) more or less glandular; rays 



purple: dry open woods in Lake and Cook counties, 



not common. Aug. -Sept. Large-leaved Aster 



A. 7nacrophyllus L. 



5. Peduncles and involucres not glandular; rays white or 

 lavender. 

 6. Heads 6-8 mm high; inflorescence forking; leaves 

 pubescent beneath; wooded bluffs and ravines, 

 locally in western and northern 111., extending east- 

 ward and southward to McHemy, La Salle, Taze- 

 well, and Calhoun counties. Aug.-Sept. Forked 



Aster A. furcatus Burgess 



6. Heads 8-10 mm high; inflorescence compact; lea\es 

 nearly glabrous; wooded ravines in Marshall, 

 Peoria, and Tazewell counties. Aug.-Oct. [A. 

 schreheri sensu Fern. ex. p., non Nees] Chase Aster 



A. chasei G. N. Jones 



4. Heads paniculate; bracts narrow, attenuate or acute, less 

 than 1 mm wide, glabrous or nearly so on the back, or 

 the margins sparsely ciliolate; achenes flattened. 

 7. Bracts acute with conspicuous rhombic green tips; stem 

 .slender, often somewhat zigzag, glabrous or sparsely 

 pubescent in decurrent lines above; leaves thin, cor- 

 date-ovate, sharply and conspicuously serrate, the 

 lower surface sparsely pilosulous, at least along the 

 veins, vai'ying to nearly or quite glabrous, the jjctioles 

 slightly or not at all margined; heads usually numer- 



